FIG. 10 is a block diagram showing a conventional transmitting output control circuit. Power amplifying apparatus 2 used in this transmitting output control circuit 1 includes diode 5 of detector 4a and coupling capacitor 6 besides power amplifier 3.
When a dynamic range necessary for detecting a transmitting output signal level is small, detector 4a can be formed of diode 5 built in power amplifying apparatus 2, load resistor 8 used for outside smoothing circuit 7 and smoothing capacitor 9. On the other hand, when the dynamic range necessary for detecting the transmitting output signal level is large, an output level of power amplifying apparatus 2 is detected by keeping isolation of signal output terminal 18 from amplifier output terminal 11 enough using directional coupler 10, detector 4b and first terminating resistor 14 at the outside of power amplifying apparatus 2.
For example, Unexamined Japanese Patent Publication No. H7-212256 is known as a prior art reference of the present invention.
According to transmitting output control circuit 1 having a conventional structure mentioned above, when the dynamic range necessary for detecting the transmitting output signal level is large, diode 5 which has been made into IC can not be used. Therefore, another detector 4b is needed at the outside of power amplifying apparatus 2 too, so that downsizing of the circuit is difficult.